


All We Need (Or, Serendipity and the Fortunate Mating Incident)

by inkstiel (Theconsultingdetective)



Category: Supernatural
Genre: A/B/O, Alpha!Dean, M/M, Mating, Omega!Castiel, Pheromones, Rut, heat - Freeform
Language: English
Status: Completed
Published: 2015-05-13
Updated: 2015-05-13
Packaged: 2018-03-30 07:59:37
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,752
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3929071
Author URL: https://archiveofourown.org/users/Theconsultingdetective/pseuds/inkstiel
Summary: <blockquote class="userstuff">
              <p>From a prompt by <a href="http://cockleddean.tumblr.com">cockleddean</a> on tumblr: Dean and Cas are mated, but they don't know it. When Dean takes Cas to a doctor's appointment, they finally realise it.</p>
            </blockquote>





	All We Need (Or, Serendipity and the Fortunate Mating Incident)

         "No, no," Dean dismissed into the phone, digging through his deep pockets filled with loose change and receipts for his keys. "It's no trouble, Cas. I'll be there in a few minutes. Yeah, I understand. Okay. I will. See you then." He tucked his phone back into his pockets, chucking some of the undesirable contents onto the hall table, and let out a little laugh when he thought back to the Unfortunate Phone Debacle of 2014. 

He was finishing a routine phone call with Cas (just a check-in, like the duo were wont to do before they moved into Dean's apartment together four months ago for 'entirely pragmatic reasons,' they both insisted) when, instead of saying "Bye, buddy," or "See you around," Dean let slip an "I love you" like it was as easy as falling out of bed. What was weirder, however, was how Cas reacted; he repeated the sentiment, "I love you too, Dean," with no trace of surprise or concern, like it was something they did every day. They'd both waited a beat before mumbling, embarrassed, and hanging up. Luckily, Dean hadn't done it since (but that didn't make the sentiment they'd exchanged any less true.) 

         Dean drove to Cas' work, where the in-heat Omega waited under the front awning of the coffee shop where he barista'd.  
"Hey," he greeted, parking the car as he stepped out, alpha pheromones trailing behind him like a big banner that read 'mine mine mine,' even though technically that wasn't true.  
"Hello, Dean," Cas greeted, standing. Dean took his elbow and took him to the car, Cas scoffing a little at the gesture. "Dean, I'm in heat, I'm not pregnant," he teased, Dean rolling his eyes as he helped him into his seat.  
"You're not far from it," he replied, closing Cas' door and walking around to climb into the driver's seat.  
"What does that mean?" Cas asked, snapping his seat belt. Dean shrugged.  
"I mean, as an...you know, an objective, unmated alpha, I...noticed. Your pheromones. Especially this year," he pointed out. "I don't remember your heats always comin' so strong."  
"Neither do I," Cas agreed. "That's why I'm going to see Doctor Barnes. I'm hoping she can explain things." He paused. "Thank you for the compliment, by the way. You smell quite...strong yourself." Dean nodded, a little blush filtering up the back of his neck around to his ears, and he was grateful for the high collar of his leather jacket.  
"Shucks," he dismissed.

The drive to Doctor Barnes' office was uneventful; the two of them chatted a little, windows down so Dean's knot wouldn't come up at the smell of Cas. They were friends, dammit, he thought, not mates. The smell of his best friend's heat shouldn't tempt him so much. When they arrived, Dean with a hand at Cas' shoulder to help him along, and checked in, the receptionist nodded and told Cas to go on back.  
"We'll take good care of him, don't worry," she smiled to Dean, confidentially. Dean nodded seriously.  
"Yeah, good," he agreed, having a seat in the waiting room and willing the pheromones coming off of himself that even he could smell to die down. Not like he was _with_ Cas, for god's sakes. 

         "Well, hey there, Cas," Pam smiled. "How've you been?"  
"I'm good," Cas nodded, sitting on her paper-covered exam table, in only his shirt and baggy boxers. "My heat is raging, though, as I'm sure you can tell, and I had some questions..." Pam, who was luckily a beta, and therefore unclouded by attraction to Cas, nodded.  
"I could smell your pheromones from the hallway," she agreed. "What's up? Found yourself a mate, huh?" Cas furrowed his brows.  
"No...I'm afraid not. I haven't really wanted one, frankly." Pam hummed. 

"Funny," she said, taking out a blood pressure cuff. "Your heats are more intense now, huh?" Cas nodded again. "And when did you start noticing this change?" Cas shrugged.  
"Maybe four months ago," he replied. "Why? Does that mean something?" She hummed.  
"Not necessarily," she answered, fastening the blood pressure cuff around Cas' arm when he offered it and steadily squeezing the pump. "People's heats and ruts can change as they age, but usually it's a sign of becoming mated, since your body gets the urge to have pups even more when your special someone is around." Cas nodded. "What were you up to four months ago, if you don't mind me asking?"  
"Let me think..." Cas hummed. "Um...well, four months would make it February...I moved in with Dean, then, and my sister had her first child, a son...nothing much else of note. Nothing romantic, I don't even think I had sex, not once." Pam hummed, checking the readout of the blood pressure. 

         "Who's this Dean guy?" she asked, glancing up from her clipboard. Cas shrugged.  
"Just a friend."  
"You're close?"  
"Very."  
"And lemme hazard a guess about something else...he's an alpha, is that right?" Cas raised his brows.  
"I suppose you had a thirty percent chance of accuracy there," he replied, a little incredulous. "Yes, he is."  
"A strong alpha? Kind of a macho type, gets around?" Cas' dark brows knitted.  
"Yes...but I don't see how all this is pertinent..."'  
"Just bear with me, here," Pam requested. "How much do you know about his ruts? When they occur, the intensity?"  
"Well, occasionally they overlap with mine," he told her, after thinking for a moment. "And his intensity...I couldn't speak to that. But I know he has to stay separate from me when they happen..." Cas stopped short. 

"You don't think..." Pam nodded her head from side to side, in uncertainty.  
"It might be," he said. "Mating by association's more common than most would figure. You build up a connection with someone, especially someone like Dean who's such an alpha, and you're mated without even sinking your teeth into each other." Cas was wide eyed.  
"So, we're mated? It's easy as that?" Pam laughed.  
"That's right," she smiled. "You don't seem too upset." Cas flushed slightly and looked down.  
"Dean is...attractive. And smart, and kind, and he's gentle, and I need someone gentle." He smirked slyly. "And I could use someone to help me through my heats, and from what I hear, he's the right person for that job." Pam wolf-whistled.  
"Someone's gonna get some," she laughed. 

"Well, while you're here, we might as well perform a checkup or two." Cas nodded as she tucked her stethoscope into her ears and pressed the cold metal circle to his chest. It was a nice relief from the heat pricking his body, doubled by the flush that came over him when he thought of Dean as his mate, when he thought of them together, helping each other through their heats and their ruts. He was almost eager to tell Dean, though there was a trace of fear in him that Dean wouldn't want to be his mate, that he would be upset, and maybe Cas wouldn't be good enough for him. 

"Can this be undone?" he asked Pam as she listened to the thud of his heart. She pulled the stethoscope from her ears.  
"The mating?" she asked, considering momentarily. "Well, sort of. You could move away from each other, and maybe you could find another mate since there's no bite. But you'd always feel like you were missing something, and you'd never get as close to your new mate as you are with Dean. Your bond seems pretty strong, if you've synced up your heats and your ruts already." Cas nodded, looking to the charts on the wall to occupy his worried mind.  
"If he doesn't want me..." he muttered, just as Dean opened the exam room door, almost as though to answer his question. 

          "Cas, goddamn, you're taking forever," he stated, standing in the doorway. "I know, Dean. Pam and I have been talking, and we have some big news." Pam's addicted under her breath, and she nodded fervently.  
"You sure enough do," she nodded. "Your pulse is off the charts, and..." She set a hand on his forehead. "You're burning up." She laughed. "You two are in deep."  
"We are?" Dean asked. "In deep with what? What's wrong with Cas?" he took a step forward, pheromones that smelled like warmth and whiskey to Cas radiating from him.  
"Nothing, Dean," Cas assured. "It seems as though we've mated," he explained haltingly. "By association. We got so close and I suppose our bodies just...decided we were mated." Dean looked at him for a second, blondish brown eyebrows crawling up his forehead.  
"We're mated? You and me, for real?"  
"That's right," Cas nodded, and Dean broke out into an unabashed grin, Cas doing the same.  
"Wow," he breathed, going for Cas' hand, their fingers lacing easily. "That's crazy, man. That's crazy." Cas nodded.  
"I can't believe it either," he agreed. "I just told Pam our ruts and heats were coordinated, and that you were such a strong alpha..." At that, Dean's eyes seemed to flash, heat and need behind them.  
"Damn right I am," he growled, though there was still a huge, harmless smile on his soft lips. "Doc? Are we finished here?" Pam raised her brows.  
"We are," she agreed. "Why don't you two boys go make up for lost time?" Dean and Cas beamed eagerly at each other, the air filling with their mingling scents.  
"Don't forget your clothes, Cas," Pam advised, but Dean just smirked at her in reply.  
"I don't think we'll be needing those," he teased, looking at Cas with so much love and desire at the same time, making Cas want to melt at his feet in a puddle.  
"I don't think we will either," Cas agreed, rising to his feet, the two of them staring at each other in it utter adoration. 

By that night, Dean and Cas were both covered in sweat, hickeys, and the sweet scent of each other, spooned together happily in Dean's big, comfortable bed.  
"Fuck, this is nice," Dean murmured, nosing at their mating mark, which was still sore and healing.  
"Mm-hm," Cas purred, pressing his hips back against Dean. "Don't know why we didn't do this sooner." Dean hummed.  
"Guess we were just...I dunno. Scared." He pressed a kiss to the back of Cas' neck, smiling contently. "But hey. We're here now, and you've got me, and I've got you. And that's all we need."  
"That's all we need." 

**Author's Note:**

> Hope everyone enjoys this fic, especially cockleddean. 
> 
> P.S. I'm on Tumblr too~@ [beecoveredcas](http://beecoveredcas.tumblr.com)


End file.
